Ribbon-reverse mechanism



J. A. HAGERSTROM.

RIBBON REVERSE MECHANSIM.

APPLICATION FILED MAY16,1918.

Patented Dec. 14, 1920.

3 SHEETS-SHEET 1.

J. A. HAGERSTROM.

RIBBON REVERSE MECHANSIM.

APPLICATION FILED MAY 16, I9I8.

Patented Dec. 14, 1920.

3 SHEETS-SHEET 2.

I II J l J. A. HAGERSTROM.

RIBBON REVERSE MECHANS IM.

APPLICATION FILED MAY 16, 1918.

1,362,098. Patented Dec. 14, 1920.

3 SHEETSSHEET 3.

PATENT OFFICE.

JOHN A. HAGERSTROM, OF SCRANTON, PENNSYLVANIA, ASSIGNOR. TO VICTOR TYPE- WRITER COMPANY, OF SCRANTON, PENNSYLVANIA, A CORPORATION OF NEW YORK.

RIBBON-REVERSE MECHANISM;

Patented Dec. 14, 1920.

Application filed May 16, 1918. Serial No. 234,923.

Ribbon-Reverse Mechanism, of which the following is a specification.

This invention relates to typewriting machines and has for its object to provide an improved construction, combination and arrangement of parts in or connected with the ribbon-reversing mechanism. One of the objects of my invention is to provide improved means for automatically varying the printing points on the ribbon corresponding to the successive reversals in direction of the ribbon feed and in this manner prolonging,

the life and providing for a more efficient utilization of the ribbon. In pursuance of this end, the invention contemplates ribbonreverse mechanism which after it has been set into operation by the ribbon, will be subjected to an idle period of variable duration before the ribbon-reversing movement is consummated. By this means the last point impinged upon by a type bar in any given run of the'ribbon is seldom the same for any other run. Another object of invention is to provide improved means for preventing the simultaneous interlocking of the ribbon driving connections on opposite sides of the machine which often results in looking the main drive shaft and rendering the typewriter inoperative. This sometimes occurs when the beveled driving gears are incorrectly spaced on the drive shaft so that a. given endwise displacement of the drive shaft will cause the gears at one side of the machine to come into mesh before the gears on the opposite side have moved out of mesh. Under this condition of things, any subsequent shifting movement of the carriage is quite likely to cause the motor draw band to become displaced. In order to provide suitable and efficient means for overcoming these difliculties, the present invention, according to the embodiment shown on the drawings, contemplates the arrangement of cams on the drive shaft with their webs in close uxtaposition to the bevel gears. These webs are adapted to have running contact with the peripheries of the gears carried by the transmission shaft so that at each endwise shift of the main drive shaft, its movement is limited and if the gears thereon have been properly spaced, it is rendered impos' sible for the bevel gears to be moved beyond thelr proper intermeshin positions. According to this invention, said cams are each provided with a plurality of cam lobes which pro ect from the webs of said cams parallel to the main drive shaft. These lobes are of sufiicient extent and those on one slde of the machine are staggered with respect to those on the other side of the machlne so that not only is a full endwise movement provided for at each reverse in the ribbon movement, but this arrangement otthe cam lobes positively prevents the main drive shaft from being left in a midway posltion in which it would not be connected up with either transmission shaft.

Other and further objects of invention will appear in the specification and be pointed out in the appended claims, reference being had to the accompanying drawings, in which:

Figure 1 is a general plan view of portions of a typewriting machine constructed in accordance with the principles of this invention, those parts of the machine not directly related to my invention being omitted for the sake of clearness;

Fig. 2 is an end elevation of the same, parts being broken away;

Fig. 3 is a top plan view of the ribbonwinding mechanism, showing contiguous portions of the machine frame and ribbon controlled parts Fig. 4 is a similar view with the parts shown in different positions;

Fig. 5 is an elevation taken from above in Fig. 3;

Fig. 6 is a side elevation of the locking rocker;

Fig. 7 is a side elevation from the left side of Fig. 6;

Fig. 8 is a rear elevation of the main drive shaft showing relative positions of parts of the ribbon-reverse mechanism with respect thereto.

Referring to Fig. 1, the drive shaft 1 is journaled in bearings 2, carried by the machine frame. Keyed to the drive shaftl are beveled gears 3 and 4, which preferably are in close juxtaposition to the shifting cams 5 and 6, which are provided with lobes 7 and 8, therebeing in this embodiment of my invention but two cam lobes on each cam, which are arranged diametrically opposite and the lobes of each cam are staggered with/respect to the lobes of the other cam. Bevel gears 3 and 4 are adapted to alternately mesh with bevel gears 9 and 10 which are respectively keyed to power transmitting shafts 11 and 12 which, according to Fig. 2, are inclined upwardly and forwardly from the drive shaft 1. The webs of cams 5 and 6 project from the drive shaft 1 to such an extent that when the drive shaft 1 is shifted endwise, one or the other of said webs comes into running contact with that one of the bevel gears 9 or 10 which happens to be brought into mesh at that time. Said cams therefore prevent an overthrow of the drive shaft 1, as pointed out above, and at the same time provide suitablemeans for locating the. bevel gears 3 and 4 on thedrive shaft for such artisans as the assemblers and outside repair men. The following description is similar for each end of the machine, but for the sake of convenience will be confined to but one end. Transmission shaft 12 carries at its upper end a bevel gear 13 which meshes with abevel gear 14 keyed to a spool shaft 15 which is adapted to receive a ribbon spool 16. A ribbon 17 as it is drawn from the spool 16 passes about a fixed axis abutment 18 and between it and a movable abutment 19, which in the present embodiment is constituted by a curved portion of a lever arm 20, which is journaled at 21 in the frame of the machine and rigid with a holding arm or lever 22. The rear extremity of the lever arm 22 normally presses against the upper end of an arm 23 of an interponent lever having a wide U- shaped portion 24 journaled on the transmission shaft 12. At its rear end, the lever 24 is provided with an operating arm 25 which extends inwardly and upwardly to arrange its rear endover the drive shaft 1. Journaled thereon is a cam roller 26 which is adapted to cooperate with the cam lobes 8 for shifting the drive shaft endwise on its axis. Projecting downwardly from the rear end of the arm 25 is a locating finger 27 which is adapted to bear against the drive shaft 1 in such a manner as to positively locate the cam roller 26 with respect to the edges of the cam lobes 8 by which it is actuated. Referring now to Figs. 3 and 4,

' a spring 28 has its opposite ends connected to the holding arm 22 and a bracket arm 29 respectively, said spring operating to impart to the holding arm 22 a normal tendency to prevent the interponent lever dropping into operative position. In order to provide the necessary leeway for the ribbon between the fixed and movable abutments 18 and 19, the outer end of the lever arm 20 may be provided. with a finger 30 which may be bent more or less to engage a rigid portion of the frame when the parts are in the desired positions. Keyed to the spool shaft 15 is a star wheel 31, which, as it rotates with the ribbon spindle causes the points or lugs of the star wheel to pass successively over the upper end of a dog 32 which swings about a pivot 33, (see Figs. 6 and 7), carried by a forwardly projecting arm 34 of a rocker or locking member 35. The dog 32 and rocker 35 are preferably made of non-magnetic material such as brass which obviates any troubles which might occur in the presence of large charges of electricity or magnetism. Said rocker is provided with a pair of oppositely disposed pins or trunnions 36 which fit into suitable depressions in the machine frame and serve as a rocking axis for the locking member. From aninspection of Fig. 4 it will be seen that the rocker 35 is relatively heavy in the rear of the pins 36 so that its normal tendency is to raise the arm 34 with the dog 32. Normally, however, this tendency is resisted by the rear end of the holding lever 22 when in the position it occupies in Fig. 3. For this purpose the rocker 35 is provided with a downwardly deflected finger 37 which rests directly upon the holding arm 22. On the forward arm 34 of the rocker 35' is a small...

pin or stop 38 which prevents the dog 32 from oscillating in one direction, but permits it to oscillate in the opposite direction, so that when the ribbon spool is rotating in one direction, the lugs or points of the star wheel 31 displace the dog 32 so as to pass readily to permit an easy feed of the machine. Let it be assumed now, that the ribbon 17 has reached a certain point in its travel when a buckle or other rigid body 38, carried thereby, is brought between the fixed abutment 18 and the movable abutment 19 (see Fig. 4). The effect of this condition is to oscillate the holding arm 22 to release the arm 23 of the interponent lever which is therefore permitted to become operative in effecting the shift movement of the drive shaft, in the manner to be presently pointed out. At the same time, the finger 37 being released drops under the unbalanced weight of the rocker, so that the dog 32 is elevated. As soon as the direction of movement of the ribbon has been reversed, the reverse move ment of the star wheel 31 is resisted by the (log 32 which is now held against an oscillatory movement on the pin 33 so that one of the points or lugs of the star wheel 31 acts as a cam on the upper end of'the dog 32 and thus depresses the arm 34 of the rocker 35 and lifts the locking finger 37 which has prevented the rear movement of the holding arm 22. Inasmuch as the moving abutment 19 has now returned to normal position, the spring 28 draws the holding arm 22 into engagement with the lever arm I far.

23 and thus raises the cam roller 26 out of the way of the cam lobes 8 on the drive shaft. The parts are thus set for another operation. As shown in Fig. 5, the lever arm 20 isdisposed within a slot 39 in the curved wall of the sppol housing. This wall is provided with a ribbon slot 40 with an opening 41, communicating therewith for the introduction and removal of the ribbon. Referring now to Fig. 8, the drive shaft 1 has keyed thereto a collar or spool 42, between the spaced flanges 43 of which projects a pin 44 carried by one arm of an angle lever 45 which is journaled on a stud 46 and provided with a cam segment 47 provided with adjacently disposed notches 48,

the inclined walls of which intersect in a point so as to prevent the formation of a neutral point for the yieldably pressed member which cooperates therewith. Said yieldable member is provided in the preferred embodiment of my invention by a lug or projection 49 carried by the lower end of a swinging arm 50 which is pivoted on a stud 51 on the machine frame. A spring 52 is maintained in compression between the frame or bracket and the arm 50 in such a way as to yieldably retain the lug or projection 49 in either of the notches 48. It will be understood from this description that after, according to Fig. 8, the shaft 1 Was moved endwise toward the right, the cam segment 47 would be raised until the lug 49 moved over into the lower notch 48 when the pressure of the spring 52 would be utilized in completing the reciprocatory move ment of the drive shaft. The operation of the ribbon controlled mechanism has already been described. From an inspection of Fig. 8 it will be. evident that whenever the arm 23 is released, the cam roller 26 falls. If it happens that one of the cam lobes 8 is directly beneath said cam roller, its falling movement is interrupted until said cam lobe has moved out from under it, when it immediately drops into position to engage the falling cam lobe which brings about the shifting movement of the shaft. As hereinbefore pointed out, the locating finger 27 prevents the roller 26 from droppin too It will be understood that in this operation, the lever 19 is'actuated at any instant that the buckle 38 comes between it and the fixed abutment 18. This instant occurs independently of the angular disposition of the cam lobes 7 and 8 with respezt to one or the other of cam rollers 26. It follows therefore that a roller 26 may fall immediately into the angular notch between the cams 7 or 8 or on to the peripheral surface of one of said cams 7 and 8. In the latter event, said roller 26 is sustained from falling into operative position for a variable period of time depending on the angular position of cam lobe 7 or 8 at the moment it comes into engagementtherewith. It will be seen therefore that whenever one of the levers 19 is actuated, the ribbon reverse movement may follow immediately or be deferred for a variable period of time depending upon the extent of the peripheral surface of the cam lobe 7 or 8 over which it must be moved before it falls into operative position. The result of this movement is that the ribbon areas which come over the printing point are continuously varied in such a way as to secure maximum efliciency from a given length of ribbon.

1 claim 1. In a typewriting machine, ribbon-winding mechanism, and means for reversing the action of said ribbon-winding mechanism, including an element adapted normally to prevent the operation of the ribbon reverse mechanism, and means under the control'of said element for locking said element in a position which permits the ribbon reverse mechanism to become operative, said element being operatable bythe movement of said ribbon to permit said locking means to become operative on said element to lock it in release position.

2. In a typewriting machine, ribbon-winding mechanism, an interponent lever, a lever normally holding said interponent lever inoperative, said holding lever being adapted to be moved by the typewriter ribbon for releasing said interponent, and means movable into and out of position to lock said holding lever in release position, said holding lever in operative position preventing the operation of said locking means, said locking means being under a normal tendency to move into locking position and provided with means operated by a reverse movement of the ribbon-winding mechanism for moving said locking means to release said holding lever.

3. In a typewriting machine, ribbon-winding mechanism, an interponent for reversing the direction of winding of said winding mechanism, means normally holding said interponent inoperative, said holding means being movable to release position by said winding mechanism near the end of its movement in one direction, means for locking said -holding means in release position, saidlocking means being operatable by-said ribbonv winding mechanism to release said holding means.

4. in a typewriting machine, ribbon-winding mechanism, means for reversing the direction of movement of said ribbon-winding mechanism including an interponent. means for holding said interponent inoperative and movable by said ribbon-winding mechanism into position to release said interponent, and a rocker member provided with a portion movable into and out of position to lock said holding member in release position, and another portion adapted to be engaged by a part of said rocker member for moving said rocker into release position. 5. In a typewriting machine, a main drive shaft reciprocable on its axis, spool shafts spaced therefrom, shafts for transmitting power from said drive shaft to said spool shafts alternately, means for shifting said drive shaft endwise including an interponent lever oscillatable about, the axis of each power transmission shaft, a lever for holding said interponent lever in inoperative position, said lever being movable by the ribbon near the end of its movement in one direction, a rocker adjacent each spool shaft, said rocker being provided with an arm adapted to look said holding lever in release position and another arm by which the rocker may be rocked, means tending to move said rocker into locking position, said holding lever nor mally preventing such movement, and means carried by the ribbon shaft for operating said rocker.

6. In a typewriting machine, a ribbon winding mechanism comprising in combination a driving shaft, a pair of spool shafts carrying ribbon spools, means for operatively connecting each of said spool shafts with said driving shaft, ribbonreversing means associated with each spool shaft for operatively connecting up one of said spool shafts and disconnecting the other, fixed and movable abutments adjacent each of said spools, said fixed and movable abutments being adapted to accommodate members carried by a ribbon for displacing the movable abutment, and means controlled by said movable abutment, for operating said ribbon reversing means.

7. In a typewriting machine, ribbon winding mechanism comprising in combination a driving shaft, a pair of spool shafts carrying ribbon spools, gearing for each of said spool shafts for operatively connecting each of said spool shafts with said driving shaft, means associated with each spool shaft for operatively connecting one of'said gearings and disconnecting the other, a fixed abutment adjacent each of said ribbon spools, a movable abutment arranged adjacent each of said fixed abutments, said movable abutment being adapted to be displaced by members carried by a ribbon adjacent its ends as said members pass between said abutments, and means controlled bv said movable abutment for actuating the connecting and disconnecting means.

8. In a typewriting machine, ribbon winding mechanism comprising in combination a driving shaft, a pair of spool shafts carrying ribbon spools. gearing for each of said spool shafts for operatively connecting each of said spool shafts with said driving shaft, means associated with each spool shaft for operatively connecting one of said gearings and disconnecting the other, an abutment adjacent each of said ribbon spools, a lever having a portion providing an indirect passage for a ribbon around said abutment, said lever being adapted to be moved by an enlargement carried by said ribbon between said abutment and said lever, and means controlled by said lever for actuating the connecting and disconnecting means.

9. In a typewriting machine, a drive shaft, ribbon spool shafts, means for alternately connecting and disconnecting said drive shaft and each of said ribbon spool shafts,

ribbon operated means for controlling the operation of said connecting and disconnecting means, said ribbon operated means including a lever arm movable into and out of operative position and provided with a deflected end portion adapted to engage said drive shaft for determining its proper operative position. 85

10. In a typewriting machine, a drive shaft reciprocable longitudinally, power transmitting shafts arranged near opposite ends of said drive shaft, said shafts being provided with gears which are thrown into and out of mesh by the axial reciprocation of said drive shaft, a lever j ournaled on each transmission shaft, means carried by said drive shaft and levers for alternately reciprocating said drive shaft, said means being 95 movable into and out of engagement by the movements 'of said levers, and ribbon controlled means for moving said levers.

11. In a typewriting machine, a drive shaft reciprocable longitudinally, power 0 transmitting shafts arranged near opposite ends of said drive shaft, said shafts being provided with gears which are thrown into and out of mesh by the axial reciprocation of said drive shaft, a lever journaled on each 1 transmission shaft, means carried by said drive shaft and levers for alternately reciprocating said drive shaft, said means being movable into and out of enga ement by the movements of said levers, an trolled means for moving said levers, said levers being provided with deflected ends adapted to engage the drive shaft for limiting their approach thereto.

12. In a typewriting machine, a drive 1 shaft reciprocable longitudinally of its axis, power transmitting shafts, said shafts being provided with gears by the reciprocation of said drive shaft to connect up one or the other of said transmission shafts with said 120 drive shaft, cams mounted on said drive shaft at difi'erent points in its length, levers journaled on said transmission shafts and adapted to move into and out of position to be engaged by said cams for shifting said 1 drive shaft, said cams being provided with axially projecting lobes and said levers being provided with contact bearings to engage the edges of said lobes and with deflected ends adapted to engage the drive 0 ribbon con- 110.

shaft reciprocable longitudinally of its axis,.

power transmitting shafts, said shafts being provided with gears adapted by the reciprocation of said drive shaft to connect up oneor the other of said transmission shafts with said drive shaft, cams mounted on said drive shaft at different points in its length, levers journaled on said transmission shafts an sides which intersect without a neutral point between said notches.

17. In a typewriting machine, the combination with a drive shaft, of ribbon-reverse mechanism including a cam arm controlled by the ribbon and a cam mounted on said shaft for engaging said cam-arm, said cam having portions which sustain said cam arm out of operating engagement for a variable period of idle movement.

18. In a typewriting machine, ribbon actuated means, a power shaft, and means for adapted to move into and out of position to operably connecting said ribbon actuated be engaged by said cams for shifting said drive shaft, said cams comprising lobes and having the cam lobes at one point of the drive shaft angularly displaced with respect to the cam lobes at another point on the drive shaft.

14:. In a typewrlting machme, ribbon re- I versing mechanism, a drive shaft reciprocated by said ribbon-revers ng mechanism, and means for holding said drive shaft against endwise movement except when ac- 25 tuated by said ribbon reversing mechanism, said holding means comprislng a collar keyed to said drive'shaft, a lever pivoted on a fixed axis, said lever having an arm slldably engaging said collar, and notches angularly spaced with respect to said axis, and means yieldably engaging said lever in either of said notches. v

15. In a typewriting machine, ribbon reversing mechanism, a driveshaft reciprocated by said ribbon-reversing mechanlsm, and means for holding said drive shaft against endwise movement except when actuated by said ribbon reversing mechanism, said holding means compris ng a collar keyed to said drive shaft, a lever pivoted on a fixed axis, said lever having an arm slidably engaging said collar, and notches angularly spaced with respect to said ax s, and means yieldably engaging said lever in either of said notches, said yieldable means comprising a yieldable detent lever plvoted on the frame of the machine and carrying a lug or projection for entering said notches.

16. In a typewriting machlne, ribbon reversing mechanism, a drive shaft reclprocated by said ribbon-reversing mechanlsm, and means for holding said drive shaft against endwise movement except when actuated 'by said ribbon reversing mechanism, said holding means comprising a collar keyed to said drive shaft, a lever pivoted on a fixed axis, said lever having an arm slidably engaging 'said collar, and notches angularly spaced with respect to said axls, and means yieldably engaging said lever 1n either of said notches, said yieldable means comprising a yieldable detent lever pivoted on the frame of the machine and carrying a lug or projection for entering said notches, said notches being provided with inclined means to said power shaft, said connections including interengageable elements movable respectively by said ribbon actuated means and power shaft, one of said elements after it is moved having an idle period of variable duration.

19. In a typewriting machine, ribbon actuated means, power driven means, a cam arm under the control of said ribbon-actuated means, and a cam driven by said power driven means, said cam being provided with portions which sustain said cam arm in inoperative position during a variable period of idle movement and which subsequently to said idle movements actuate said cam arm for elfecting a reverse of the ribbon movement.

20. In 'a typewriting machine, amain drive shaft, and a ower transmitting shaft, one of said shafts aving an endwise movement relative to the other, gears on said shaft movable into and out of 'mesh by said endwise movement, one of said gears being provided with-a web or projection extending beyond its periphery and adapted to have running engagement with the periphery of the other gear for limiting the endwiseniovement of said shaft, and ribbon-reverse means controlling the endwise movement.

21. In a typewriting machine, a main drive shaft, a shaft for transmitting ribbon feed movements from said drive shaft, said shafts being movable into and out of power transmitting relation to each other and having interengageable parts which are moved into and out of engagement by the relative movement of said shafts, a cam provided with a web portion in juxtaposition to one of said interengageable parts which transmit motion between said shafts, and a ribbon controlled arm movable into and out of position to engage said cam for imparting relative movement'to said shafts, said web portion of the cam being adapted to engage the other of said interengageable parts to limit the relative movement of said shafts.

22. In a typewriting machine, a mailni drive shaft, a shaft for transmitting ribbon feed movements from said drive shaft, said shafts being movable into and out of power transmitting relation to each other and having interengageable parts which are moved into and out of engagement by the relative movement of said shafts, a cam provided with a Web portion in juxtaposition to one of said interengageable parts which transmit motion between said shafts, and a ribbon controlled arm mova 1e into and out of position to engage said cam for-imparting relative movement to said shafts, said web portion of the cam being adapted to engage the other of said interengageable parts to limit the relative movement of said shafts, said cam having portions which project laterally from said web portion and sustain said cam arm for an idle period of variable duration.

23. In a typewriting machine, ribbon actuated mechanism for reversing the direction of movement of the ribbon feed, including cam arms, laterally spaced power transmitting shafts, an endwise movable drive shaft, said power transmitting shafts andmain drive shaft being provided with gears for connecting said drive shaft with said transmission shafts in alternation, and cams keyed to said drive shaft adjacent to the gears thereon and constituting guards or stops adapted to' engage the gears on said transmission shaft to limit the endwise movements of said drive shaft, said cams and cam arms being adapted to interengage to impart the endwise movements to said drive shaft.

JOHN A. HAGERSTROM. 

